I am trying to use ODR in our application and have created Tags and grouped it under Initial Install Tags option under Prefetched.
According to WWDC https://developer.apple.com/videos/play/wwdc2015/214/
1) You can verify ODR by using the disk section of debug navigator in X Code
However as of XCode 8.1 beta the initial install tag does not deem to work as expected. As you can see in the screenshot attached.
2) According to the my understanding of WWDC this should work on Archive version and also on Simulator by simply running the app from XCode. Not only TestFlight
3) I do not believe that you should have to use a separate fetch request, but as this seems to be the only way to get it working, this should be seen as a workaround rather than a solution. According to the documentation
Initial install tags. The resources are downloaded at the same time as the app. The size of the resources is included in the total size for the app in the App Store. The tags can be purged when they are not being accessed by at least one NSBundleResourceRequest object.
So in my opinion this feature is just not working as documented and expected and a bug should be filed with Apple. That seems to be the conclusion on Apple Forums
https://forums.developer.apple.com/thread/9530